The production of parts constituting electrical and electronic circuit boards often requires the mounting of several multilead electrical components on each board. Usually, such mounting techniques involve manual insertion of the leads of each multilead component in corresponding holes of a circuit board. Clearly, such techniques result in small throughput, are time consuming and labor intensive. Moreover, with electrical components, such as semiconductor integrated circuit (I.C.) packages, becoming smaller in size, and with the number of leads on each I.C. package substantially increasing to achieve higher packaging densities, the problem of operator fatigue becomes a major one.
Several attempts have been made to avoid the foregoing hindrances of manual insertion of multilead components by resorting to automation. In the area of automatically mounting multilead components or I.C. packages on printed wiring boards (PWB), the emphasis so far has been on achieving high accuracies in the positioning of a robotic hand or automatic manipulator with respect to the holes of the PWB. Such high accuracies and close tolerances in the design and control of the robotic hand result in a complex and expensive automatic apparatus for accurately positioning the leads or terminals with respect to their corresponding holes. Also, the foregoing strict hand positioning requirements do not and cannot compensate for any measurement deviations existing between the outer housing of the component to be inserted and its leads.
In a copending U.S. patent application Ser. No. 382,263 filed May 26, 1982 in the name of B. D Hoffman and B. Weismann for "Method and Apparatus for Automatically Mounting Multilead Components on Circuit Boards", and assigned to the assignee hereof and incorporated herein by this reference, there is disclosed a method for mounting a multilead component on a circuit board comprising the steps of positioning the multilead component on the board such that each lead of the component is proximate to a corresponding aperture in the board, and imparting a vibratory motion to the board to the end of realizing insertion of the leads of the component into the corresponding apertures in the board. Such vibratory motion is, however, disclosed as, in one way, being accomplished in the disclosed embodiment by mounting the board at three of its corners to a base through mounting bodies at those corners, and by imparting vibration to the board by means of a single motor mounted on the base and driving an eccentric shaft coupled to the fourth corner of the board.